This part provides the background related to the present disclosure, but is not necessarily the conventional technology.
In an existing wireless communication system, a centralized control mode is generally adopted. That is, an evolution Node Base Station (eNB) controls a communication behavior of a User Equipment (UE). In this case, the eNB needs to allocate wireless resource overhead to each UE. However, with the rapid development of the wireless communication technology, the number of UEs, service quantities and the like are increasing and being close to a carrying upper limit of the existing wireless communication system. At present, as a key wireless communication technology of the next generation of cellular communication, a Device-to Device (D2D) communication technology can bring a great performance gain to the communication system, for example, having advantages of improving a frequency spectrum usage rage, reducing a power loss of a user terminal and the like, thereby being concerned by the standardization work and academic research.
A mechanism of establishing the D2D communication generally concerned by current research is approximately as follows. In an RRC-IDLE state and an RRC-CONNECTED state, if it is detected by a base station that a UE and another communication object UE meet a D2D communication condition, such as a short distance between the UEs, the base station notifies the UEs to initiate a D2D terminal discovery and detection. When the UE is connected to the target UE successfully, it indicates that the D2D communication is established successfully, and then the D2D communication is performed.
However, an issue caused by the above process is that, the base station determines whether the UE can perform the D2D communication only based on detection on the base station side, and thus a detection condition of the base station is often instantaneous and unilateral. For a main communication body UE, the detection condition on the base station side can not effectively certify that the UE can perform and maintain an effective D2D communication.